Hera -- Astronomical Data Analysis over the Internet

Hera is the new data processing facility provided by the HEASARC at the NASA Goddard Space Flight Center for analyzing FITS format. astronomical data files. Hera provides all the preinstalled software packages, local disk space, and computing resources needed to do general processing of FITS format data files residing on the user's local computer, and to do advanced research using the publicly available data from High Energy Astrophysics missions. Qualified students, educators, and researchers may freely use the Hera services over the internet for research and educational purposes.

The Hera computer hardware includes

  • a cluster of Linux workstations to do the data analysis
  • local disk space for temporary storage of user's data and results.
  • high speed access to the terabytes of data in the HEASARC's high energy astrophysics data archive.

The Hera software includes general utility programs for processing and manipulating any FITS image or table, as well as hundreds of more specialized programs for analyzing data from high-energy astrophysics missions such as ROSAT, Chandra, XMM-Newton, Swift, and Suzaku.

The Different Flavors of Hera

Several distinctly different user-interfaces to the underlying Hera services are currently available to meet different needs.
You can
  • run majority of programs in the FTOOLS software suite from a browser without the need to download and to install FTOOLS software.
  • run individual tasks from a command line window on your desktop to analyze local FITS data files (just as if the software were installed on your local machine), or
  • use a graphical user interface to control the execution of different software tasks and manage your files on both the Hera server and on your local machine, or
  • select any data set in the HEASARC data archive using your web browser, and then click on the associated 'Hera' link to instantly start analyzing that particular data set.
These 4 different user interfaces are described in more detail in the following paragraphs.

  • Runtask Hera - This is a command-line interface to Hera that allows you to run any of the software tasks that are installed on the Hera servers to analyze data files that reside on your local computer. You execute each task the same way as you would if the software packages were installed on your local machine, by specifying the name of the task on the command line, followed by the values of any other task parameters. The only difference is that that you must preface the entire command with the string "fv -r". The 'runtask' interface then transparently copies the input data files to a temporary disk area on the Hera server, runs the task, and then copies any output text and data back to your local computer. If the task is expected to take a while to run, you may optionally request that Hera send an email notification when the task has completed, at which point you may reconnect to Hera and download the results.

  • Standard Hera - This is the graphical Hera interface that provides interactive access to all the Hera capabilities. First time users can create a new Hera ID and password to connect to the system. You can then use the Hera GUI to analyze the data files on your local machine or in your private disk area on the Hera servers. You may transfer data files between your Hera disk area and your local computer using your mouse to 'drag and drop' the files from one machine to the other. You may select additional data sets from the HEASARC's high energy astrophysics archive using the Browse web interface and save them to your Hera disk area for further analysis (no need to download the data to your local computer first). The data files on the Hera disk area are preserved between sessions so you may exit from Hera and then return at a later date to continue the analysis. (Policies for managing the Hera disk space and deleting unused data and accounts are currently under development).

  • Anonymous Hera - This version of Hera lets you instantly analyze a single data set from the HEASARC data archive. You simply use the Browse web interface to locate a data set of interest, and then click on the 'H' Hera services link that is shown next to that data set. All the data products associated with that particular observation are copied to a new temporary Hera session, and then the same Hera GUI as is used in the Standard Hera interface will start up allowing you to further examine and analyze the data. The main difference from the Standard Hera interface is that the data files in the Anonymous Hera session are deleted when the session ends, however before doing so, you are given the opportunity to copy the data to a new or existing Standard Hera account, or download the data to your local computer.

  • Web Hera (Under Development) - This is the Hera web portal to FTOOLS software. By using Web Hera, the user will not need to download or to install the HEASoft suite locally. Users can perform data analysis with HEASoft using their web browser as the software interface.

Getting Started with Hera

To learn how to effectively use Hera as quickly as possible, we recommend that you follow the steps on the Getting Started web page. Also refer to the frequently asked questions page.

Software and Hardware Requirements for Using Hera

Users may connect to Hera from most commonly used computers systems, including Unix/linux workstations and Mac OS-X PCs. Many of the Hera services can be accessed from Windows PCs as well. The only requirements for using Hera are:
  • the small Fv FITS file viewer and editor program must be installed on the local machine (version v4.4 or higher). Fv serves as the local client portal to the Hera services.
  • broadband access to the Internet
  • access to a standard web browser such as Firefox or Internet Explorer.

Important note concerning firewalls: Some Hera users have experienced problems using Hera because the firewall system on their local computer or network blocked the connection to the Hera servers. Network connections from your local machine to the Hera servers must be allowed on certain computer ports in order for Hera to function. Please contact the Hera developers for advice if you experience problems connecting to Hera.

Contacting Us

Hera is an experimental project initially funded by a NASA AISRP grant. We are interested in your suggestions and comments on how Hera can be improved. Please send any comments using the 'Mail' button in the lower right corner of the Hera GUI window, or email us directly at this address: heradev "at" athena.gsfc.nasa.gov.

The Hera development team currently consists of:

    William Pence
    Pan Chai
    Thomas McGlynn
    Laura McDonald

Previous contributors include:
    Ziqin Pan, Peter Wilson, Ning Gan, and Christina Heikkila